CENTROSOME REORIENTATION IN REGENERATING ENDOTHELIAL MONOLAYERS REQUIRES BFGF

Monolayers of endothelial cells respond to physical denudation with a characteristic sequence of lamellipodia extrusion, cell migration, and cell proliferation. Basic fibroblast growth factor (bFGF) has been im plicated as a necessary component of this process: addition of exogeno us bFGF enhances monolayer regeneration both in vitro and in vivo, and monolayer regeneration can be inhibited in vitro by treatment with ne utralizing antibodies raised against bFGF. Centrosome reorientation fr om a random location to one preferentially situated between the nucleu s and the denudation edge has been postulated as a mechanism essential for cell polarization and subsequent migration. This present study ex amined the effects of a polyclonal antibody to bFGF and suramin on mon olayer regeneration, actin microfilament staining, and centrosome orie ntation at the wound edge of partially denuded bovine large vessel end othelial monolayers. Treatment with anti-bFGF or suramin abolished mon olayer repair in these cultures. Cells at the denudation edge showed a ltered actin staining patterns and reduced lamellipodia extrusion, and there was complete inhibition of centrosome reorientation in treated cultures. Monolayer repair and centrosome reorientation could be resto red by addition of exogenous bFGF in antibody but not suramin treated cultures. Recent evidence suggests that preferential centrosome locati on in migrating cells may be a consequence of lamellipodia protrusion and cell spreading, rather than an indication of cell polarization. Ho wever, these results indicate that agents which interfere with bFGF av ailability prevent endothelial monolayer regeneration via mechanisms i nvolving cell spreading and/or centrosome reorientation. (C) 1993 Wile y-Liss, Inc.